Apparatus for making soap



july 5, 94L B, H, THURMN 2,249,676

APPARATUS FOR MAKING SOAP Original Filed Jan. 29, 1956 2 Sheets-Sheet l l l' 5;@1221 +A.

July 15, V1941. B. H. THURMAN APPARATUS FOR MAKING SOAP Original Filed Jan. 29, 1936 2 Sheets-Sheet 2 Gum/mf Patemedculy 15, 1941 APPARATUS FOR MAKING SOAP Benjamin H. Thurman, Bronxville, N. Y., assignor to Refining, Inc., Reno, Nev., a corporation of Nevada Original application January 29, 1936, Serial No. 61,410, now Patent No. 2,142,983, dated January Divided and this application December 29, 1938, Serial No. 248,358

, 2 Claims.

This invention relates to a process and apparatus for making or processing soap and the like, or for both making and processing a product such as soap. More particularly, the illustrated complete embodiment is directed to a A process and apparatus for continuously making soap in a closed system, continuously removing the glycerine therefrom during the process, and converting the soap into marketable form or into condition for further processing to form marketable soap.

The fundamental ingredients utilized-are a saponifying material, such as an aqueous alkali solution, and a saponiable material, for example, glyceride oils, fats, resin, etc. It will be clear, however, that various saponifying and saponifiable materials may be utilized.

In general, the preferred complete embodiment of the process of the present invention to be hereinafter described, consists of mixing in proper proportions a saponifying material and a saponiable material,l preferably by bringing together owing streams' of these materials in proper proportions; continuously iiowing the mixture through a heating zone; delivering the vheated products to a vapor separating zone where the water and sometimes the glycerine are removed; removing the soap from the vapor sepa.- rating zone in a dehydrated or anhydrous and substantially molten or at least plastic or semiplastic condition; cooling this soap; and, in some instances, further processing the chilled soap to produce a desired product.

It is an object of the invention to provide a process and apparatus for producing soap in a closed system and by whichv a desired soap product is obtained in a single continuous operation during which the glycerine may be removed from the soap.

I have discovered that if a hot soap of a molten homogeneous nature as distinguished from a mass of individual particles. It may be substantially anhydrous, or may contain small amounts of moisture. With most soaps this moisture content should be rather low if a friable mass is to be obtained upon cooling.

Within the meaning set forth above, it is an object of the present invention to cool such molten soap in such a manner that a friable soap is produced.

It is a. further object of the invention to process such a molten soapin such a manner, as to form -av soap in powdered Iorm.

This may be accomplished by suitably cooling to form a friable mass which is continuously broken up by mechanical means as a part of a continuous process for making powdered soap, and one of the objects of the present invention lies in the provision of a novel method and apparatus directedto this end.

On the other hand, it is sometimes possible to produce a soap mass so friable that a major portion thereof is seli-disintegrating and forms a -powder upon extrusion or upon being expelled from the cooling means. I-t is an object of the present invention to provide a, novel method and apparatus for forming this type of substantially character (within the definition of the term molten given herein) is cooled, usually out of contact with the atmosphere, a friable soap mass results as the temperature is reduced. By the term molten soap as used in this applicationv I have reference to a hot soap having little or no moisture therein and securing what iiuidity it has from theapplication of heat rather than from large quantities of water therein. 'I'he term as herein used is not limited to any particular degree of iluidity. It is suiiicient within the meaning of the term that the soap be in a plastic or semi-plastic condition. Usually it will have some flowing properties even though its flowing tendencies are very slight, and it will be of a self-disintegratingsoap which breaks up into a. powder with little or no agitation or externally applied crushing pressure.

Another object of the invention is to provide a process and apparatus by which a friable and easily worked soap product is continuously produced.

Another object of the invention resides in the provision of a process and apparatus for continuously producing a nely powdered soap product from a saponifying material and a saponiiiable material, the heat utilized in the system forming the molten soap of low moisture content and this soap being cooled out of contact with the atmosphere to form a friable product which is easily reduced to powder form.

It is also an object of the present invention to cool the soap under reduced pressure, and in many instances to cool this soap in such aman- Aner that the moisture content of the soap is not permanently increased to any substantial degree.

Another object is to cool the soap by injecting a liquid such as water thereinto, the soap being at atemperature above the boiling point of this liquid at the existing pressure, whereby at least a portion of the liquid is vaporized, the vapors being removed before the soap is cooled Sufllclent to condense any major portion of these vapors While in the soap.

I nd it convenient to discharge the reaction products resulting from the saponifying reaction into a separating chamber, from which vapors are continuously withdrawn to allow the substantially anhydrous and sometimes glycerinefree soap to separate in this chamber. One of the objects of the present invention is to supply heat to this separating chamber to obtain various advantages to be pointed out hereinafter.

Another object of the-invention is to provide a novel process and apparatus capable of producing a substantially. bleached soap product even when used with such highly colored oil as crude or reiined palm oil.

Another object of the invention is to provide a process and apparatus for continuously producing a plastic mass of soap, or a jell-like soap product comparable to what is known in the art of kettle soap making as a nished kettle soap.

A further object is to provide a process and apparatus for continuously producing a soap product conditioned to be cut or molded intobars for detergent use.

A still further object of the invention is to provide, as an article of manufacture, a new soap product of friable nature which. is self-disintegrating at least in part, or a friable soap product which is easily powdered or otherwise worked.

Other objects and advantages Willbe apparent to those skilled in the art from the following description.

Apparatus suitable for carrying out the process of the present invention is described in the following specication and shown in the attached drawings, of which:

Figure 1 is a schematic drawing of an apparatus for continuously producing a friable soap product, while continuously removing the glycer- Figure 2 is a schematic drawing of a modification of a portion of the apparatus for producing finely powdered soap;

l used in the modications of Figures 2 and 3; and

Figure 5 is a view of one of the screens or perforated plates used in the modification of Figure 3.

Referring more particularly to the drawings, in Figure 1, I0 indicates in general a mixing device for proportioning and mixing saponifying and saponiable materials; II indicates in general a heating device for heating the mixture of saponifying and saponiable materials; I2 .indicates in general a vapor separating chamber or zone in which the water vapors and in some instances the glycerine vapors are separated from the soap; I3 indicates a catch-all or trap for removing any soap masses carried over by the vapors; I4 indicates in general 'a condensing system in which the glycerine and water vapors are separately condensed; I5 indicates a conveyor for removing themolten soap from the vapor separating zone I2 and chilling the same; and I6 indicates a second conveyor vfor receiving and, in some instances, conditioning the soap from the conveyor l5.

Various types of apparatus for proportioning and mixing the saponifying and saponiable materials may be used which perform the function of eiiecting -at least some intermixture of properly proportioned materials before introduction into the heater, the materials being introduced into th;L heater in the form of a continuously iiowing stream. In the preferred apparatus the proportioning-mixing device I0 includes a pair of proportioning pumps I1 and I8 driven by any variable-speed drive means such as a motor I9, a variable-speed device 20 being interposed between the pumps so `that by :varying the speed of the motor and the relative speeds of the pumps, a proportioned stream of a saponiiying material can be drawn from a tank 2| and a proportioned stream of saponiiiable material can be drawn from a tank 22 by the pumps Il and I8 respectively. The separately y pumped streams come into contacting and mixing relationship under pressure in a mixer 23, which may merely comprise a chamber into which the pumped streams move, though additional mixing means may be provided if desired. The mixture ows in a continuously moving stream to the intake connection of the heating device II through a pipe 23' which may be provided with suitable pressure and temperature indicating devices.

'I'he preferred heating device includes a coil 24 positioned in a chamber 25 and externally heated as by an oil or gas burner shown at 26. Other means of heating this coil may be used. The mixture ofthe saponiable and saponifying materials is thus heated as a continuously .flowing stream in the reaction zone provided by the coil 24 to effect saponiflcation. After saponiiication takes place the reaction products move as a continuously owing stream toand through a means defining a vacuum Zone, this vacuum zone including the vapor separating chamber I2 and usually at least a part of the conveyor system. As shown, these reaction products are conducted to the vapor separating chamber I 2' through a pipe 21 which is preferably equipped with suitable devices for indicating pressure and temperature conditionsof the reaction products.

The vapor separating chamber I2 is shown as comprising an air-tight casing 28 Whichmay be completely surrounded by a heating jacket 2E through which a suitable heating medium may be circulated by means of connections 30 and 3l.

The pipe 21 leading from the heating device terminates in one or more nozzles 32 positioned Within the chamber I2 and the saponied material from the heating device is thus continuous- In accordance with this invention, 'the soap which accumulates in' the lower portion of the vapor separating chamber I2 is in molten condition within the meaning of this term as previously described. This soap .may thus be rather iiuid or may be in a plastic or semi-plastic condition. Its temperature will be relatively high and it will be substantially anhydrous.,

If desired, the temperature of the material leaving the heating zone may be maintained sufciently high to deliver molten soap to the bottom of the vapor separating chamber I2, they heating being carried on under such conditions of temperature and pressure that all of the water is in vapor form in the pipe 21, assuming that nozzles 32 of a constricting nature are used. vIt is often desirable to .carry the temperature high enough to liberate glycerine vapors in the reaction zone defined by the coil 24. As to the factor of pressure, a relatively high inlet pressure is maintained atd the entrance of the coil 24 of the heating device I I, either by constricting the discharge of the nozzles 32 vor by constructing the coil 24 y of small enough diameter relative to the rate of flow therethrough so that the frictional resistance to ilow maintains a relatively high inlet pressure. Even when a constricting nozzle means is utilized, this factor of frictional resistance causes further increase in inlet pressure.

- n the other hand, it is desirable in some instances to supply additional heat to the vapor separating chamber l2, though this is not always essential. For instance, if the soap mass in the vapor separating chamber I2 is below the temperature necessaryto maintain the soap in the molten condition referred to, it is desirable to increase the temperature thereof to insure that the soap in the bottom of this vapor separating chamber I2 will be in this molten condition.

Such additional heat may be supplied by use of the heating jacket 29 or it may be supplied in other ways such, for instance, as introducing superheated steam into the vapor separating chamber I2. As shown in Figure l, such steam from any suitable steam generating source, preferably in a superheated state, may be delivered to the separating chamber adjacent the nozzles 32 by means of a pipe 33. This pipe may be positioned around that portion of the pipe 21 entering the vapor separating chamber I2 so as to maintain the temperature of the materials in this pipe or to impart additional heat thereto, the steam being discharged around the nozzles 32 by annular orifice means as shown. At the same time, or alternatively, steam may be supplied through a pipe 33' so as to be discharged near the nozzles 32. Due to the law of partial pressures the introduction of steam into the vapor separating chamber I2 makes it possible to operate the system with pressures in this chamber higher than would otherwise be the case.

It will be clear, however, that if the' soap is delivered to the vapor separating chamber I2, at suiliciently high temperature, no additional heat need be supplied thereto. In this instance the heating jacket 29 surrounding this vapor separating chamber may be used to prevent heat' losses from the chamber to insure maintenance of the soap in the said molten condition, or it may be used to increase the temperature therein suillcient to prevent condensation of glycerine vapors in this chamber, or liberate additional glycerine vapors therein, or it may be used only to preheat the vapor separating chamber when the apparatus is iirst put into operation.

In the vapor separating chamber I2 the glycerine and water vapors separate from the molten soap. If glycerine is to be removed all of the glycerine may be vaporized before the reacti'on products reach the vapor separating chamber I2, or a portion of the glycerine may ilash into vapor form upon discharge into this chamber, or a portion of the glycerine may be converted into vapor form in this chamber by application of heat to the products therein. If glycerine is to be removed or recovered this chamber is .usually maintained under a relatively high Vacuum by means which will be pointed out. The vapors separated in the vapor separating chamber I2 are drawn oi through a pipe 34 leading to the catch-all I3.

A plurality of bailles35 and 35' are preferably positioned in the vapor separating chamber I2 to separate and retain therein any soap masses carried upward by the water and glycerine vapors, these baliles being so constructed that any partithe pipe 34 pass first through the catch-all I3 which separates from the vapors any soap massesv which might escape the ballles in the vapor lseparating chamber I2. vapors then passthrough a pipe 35 through the condensing system I4, which includes a glycerine condenser 31, a water condenser 3B, and avacuum pump 39 which maintains a low pressure in the vapor separating chamber I2. The glycerine' and water condensates 'may be continuously moved into -tanks 40 and 4I respectively through pipes, 42 and 43 which may be long enough to furnish suili'cient static 'head of water and glycerineto maintain the vacuum in the system.

The dehydrated, substantially anhydrous soap accumulating in the bottom of the vapor separating chamber I2 moves in the sald molten condition (i. e. in strictly molten, plastic or sennplastic condition) into the conveyor I5 which is in open communication with this chamber. Any suitable means may be utilized to assist this iiow, Figure 1 illustrating an agitator or scraper 44 mounted upon a shaft 45 extending vertically through the vapor separating chamber I2 and rotated from .any suitable source -of power through a drive means shown, for example, as gears 46 and 4l. The rotating agitator 36 insures that the soap will be delivered continuously to the conveyor I5.

The conveyor I5 is preferably of the screw conveyor type. A jacket 49 is preferably provided to surround the first portion of the conveyor housing, a suitable heating medium being circulated therethrough to prevent heat loss and to maintain the soap in substantiallyl the same condition as it was when rst withdrawn from the vapor separating chamber I2. A slight cooling is sometimes not detrimental in this first portion of the conveyor I5.

The present invention contemplates cooling the molten soap, preferably while it is subjected to subatmospheric pressure. For this purpose a second jacket 50 surrounds the end of the 'conveyor housing remote from the vapor separating chamber I2.4 A suitable cooling medium,.such as cold water, is circulated through this jacket 50 'by means of connections 5I and 52. The rate of cooling may be varied, but in general a sudden chilling ls often very desirable in forming the more friable soap products.

Other means for cooling the molten soapA may is such that the water will be immediately vaporized when introduced, heat being extracted from the molten soap in order to chill and solidify the same. The vapors formed at this stage of the process may be carried back into the vapor sep- The glycerine and water l arating chamber I2 through the conveyor l5 or through a vent pipe 56 which also leads back to the vapor separating chamber I2, thus preventing retention of any'large quantity of vapor or moisture in the soap product as it solidies and forms the friable mass. Any glycerine vapors which fail to be separated from the soap in the vapor separating chamber but which are separated in the conveyor I5, are also thus carried backto the vapor separating chamber. The entire conveyor I5 is thus maintained under subatmospheric pressure and the soap is cooled under these low pressure conditions and out of Contact with the atmosphere. Simultaneous cooling by means of both the coolingv jacket 50 and injection of cooling agents through the pipe connections 53, 54 or 55 may in some instances be desirable.

The cooled soap discharged from the first conveyor is usually a solidified, friable mass. However, it is sometimes at such a high temperature that exposure to the atmosphere would result in deleterious reactions, such as the formation of peroxides. Also it is desirable in some instances to hydrate or otherwise additionally process the soap before extrusion. The second conveyor I6 may be used in one or more of these capacities.

The cooled soap is discharged from the con- -veyor I5 into the second conveyor I6 which is preferably of the screw type. Figure 1 discloses this second conveyor as positioned .below the conveyor I5, though it will be understood that if it is a mechanical expedient,` the second conveyor may be constructed as a continuation of the first conveyor, or it may extend at right angles thereto asshown in Figure 2. The conveyors I5 and I6 may be`driven from any suitable source of power through drive connections shown, for example, asa pair of meshed gears suitably driven.

The second conveyor I6 is provided with a means for constricting the discharge therefrom. This may comprise an enlarged portion 51 of the conveyor shaft near the discharge end of the second conveyor I6. A free opening valve 58 may be provided for further constricting the discharge in certain modifications of the process herein disclosed.

One function of the second conveyor IB is to act as a Vacuum seal for the first conveyor and for the entrance portion of the second conveyor. It thus prevents entrance of air into the first conveyor and maintains the vacuum Y conditions therein. The pressure on the soap progressively increases in this second conveyor as the soap moves toward the valve 5S.

Another function which this second conveyor I6 may serve is to further cool, and in some instances hydrate, the soap delivered thereto. Hydration and cooling may be effected by introducing water or saturated steam into the second conveyor through one or more connections 59, the amount of moisture thus added being controlled in response to the desired hydrating effeot.` If water is employed in this capacity, it is often desirable that thesoap in the second conveyor be of sufciently high temperature to vaporize at least a portion of the water, thus insuring a uniform distribution of water throughout the soap. However, this is not invariably necessary, for it is often possible to secure uniform distribution utilizing the agitation present `in this conveyor. If the soap is not to ibe hydrated, cooling can be effected by circulating a cooling liquid through a jacket 60. The latter method of cooling may be used in conjunction with the 'y arating chamber I2.

addition of moisture through the connection 59 if desired.v The soap may also be cooled by spraying the cooling medium upon the external sur-face of the housing of the conveyor I6. As the soap cools, any vaporsv therein will be con' densed. Thus, if vhydration is accomplished by adding saturated steam,` or by adding water which vaporizes entirely or in'part, the vaporsmay'be condensed before discharge of the soap so that this soap may be hydrated to any desired extent in the second conveyor.

The connection 59, or other connections or means not shown, mayalso be employed for introducing llers or other soap builders into the conveyor I6, as is contemplated in certain modications of the process herein disclosed.

It is often desirable to heat the incoming sapcniiiable material to a degree proportional to the temperature of the resulting soap. This may be accomplished by circulating this saponiiiable material through the jacket 50, this material thus acting as a cooling medium and being in turn heated before being forced into the reaction zone. In other instances it is possible to circulate the saponiable material or the saponifying material through the condenser 31, thus heating the material and cooling the vapors.

While continuous screws 6I and 62 may be respectively utilized in the rst and second conveyors I5 and I6, Iv usually find it desirable to form each screw so that it provides several iiights with sections therebetween into which may extend knife bars 63 or other stationary elements. Such means utilized in conjunction with the various nights of the conveyor screws serve to effectively advance the soap and also serve to agitate the soap, in some instances effecting a milling or plodding action. The latter is especially true with reference to the means interposed between the flights of the conveyor screw 62.

Several modes of operation of the apparatus hereinbefore described may be employed, depending upon the product to be produced. In general,

,if a neutral soap is desired, the proportioning The optimum temperature and pressure at the discharge end of the heater vary with the saponifiable material utilized and with the subsequent steps of the process. However, it can be stated in general that if the soap accumulating in the separating chamber I2 is to be anhydrous and substantially liquid-free, the temperature developed in the heater should lbe sufiicient to vaporize all of the water and all or a portion of the glycerine in the reaction zone defined by the coil 24. If a constricted nozzle means is utilized, it is possible to operate the process in such a manner that any unvaporized glycerine will flash into vapor upon introduction into the vapor sep- Further, if heat is supplied to this vapor separating chamber I2, it is possible to utilize lower temperatures in the reaction zone than would otherwise be 'the case.

By way of example, and without limiting myself thereto, I have found it possible to operate arating chamber I2 without vcontinuously supplying heat thereto during the process, the lreaction products owing through the pipe 21 bev all materials and all possible modifications of the process. Regardless of where the heat is supplied, it is usually desirable that the soap 'accumulating in the lower end of this vapor separating chamber I2 be in molten condition within the denition of this term set forth above, if a friable soap product is to be produced. With.` most saponiflable materials satisfactory results can be obtained by utilizing temperatures in the pipe 21 of'from 540 to 575 F., no heat being continuously supplied to the vapor separating chamber. However, these limitsare set forth only as exemplary and can be made somewhat higher or lower without departing from the spirit of the present invention.

My experiments show that the .soap in the bottom of the vapor separating chamber need not be in strictly molten and very uid condition to obtain a friable product. Friable soap can also be obtained by cooling -plastic or semi-plastic soap as it is withdrawn from this chamber. In this connection, my experiments indicate that while there is a very definite melting point for various'soaps, once the soap has been melted the temperature can be reduced many degrees below this melting point without causing the soap ,to become solidified. This factor gives a range of permissible temperatures in the vapor separating chamber I2, the upper temperature being considerably above the melting point oi' the particular soap being produced, and the lower temperature in this range being considerably below this melting temperature but above the temperature at which the mass of soap solidiiies and departs from its semi-plastic, plastic or strictly molten condition.

If glycerine is to be recovered, the absolute pressure in the vapor separating chamber I2 should be relatively low. Pressures in the neighborhood of a few millimeters of mercury are satisfactory. The glycerine and water vapors may be removed from the vapor separating chamber I2 and condensed as previously set forth. It will be understood, however, that it is not essential to remove allof the glycerine in order to obtain a friable soap product of they nature contemplated.

Once the molten soap is produced in the vapor separating chamber I2, the subsequent steps will depend in large measure upon the desired characteristics of the final product. Various procedures are possible. y

As ay rst alternative, the product may be made so friable as to be substantially self-disintegrating, to the extent that approximately 90% of the soap mass will fall from the extrusion means of the secondvconveyor in powdered form, the remaining being also extremely friable and easily broken up-by application of slight pressure. To form such a self-disintegrating soap, it is necessary to have the soap in substantially anhydrous condition, no moisture being added it vis necessary to cool the molten soap either by use of the jacket or by injecting water or other liquid through the pipe 53, 54er 55 and removing the resulting vapors through the pipe 56. Sudden cooling is more effective in forming planes of incipient fracture extending throughout the soap mass. Further, to secure this soap of substantially self-disintegrating nature, it is usually desirable to cool the soap to such a degree that the temperature is below a predetermined value. With most soaps cooling to a temperature below 200 F. will accomplish the desired result, though in some instances it is desirable to continue the cooling to a lower temperature. With certain other soaps a satisfactory self-disintegrating soap may be obtained by cooling to a temperature which is somewhat above 200 F. With most soaps, however, this temperature will be in the range of from 180 F. to 200 F., though it will be `clear that I am not limited to this range in all instances. This degree of cooling may be obtained entirely while the soap is in the first conveyor I5, or the soap may be cooled partially in the first conveyorand partially in the second conveyor. Cooling can, of course, be carried still further in the second conveyor I6 without departing from the spirit of the invention.

As a second alternative, the apparatus may.

be operated so as to produce a Iriable soap mass which is not self-disintegrating but which is of such a friable nature that the resulting product can be broken up into a powder by crushing the y product or by screening the soap, or by equivalent disintegrating steps.

The apparatus shown in Figure 1 will produce this type of soap if the molten soap is not chilled to as low a temperature as set forth in the preceding paragraph, or if the soap is somewhat hydrated during passage through the conveyors.

In this modification of the process the molten,

substantially anhydrous soap is moved from the vapor separating chamber I2 and is rather quickly cooled in the conveyor I5 by employing the cooling jacket 50 or by injecting water through the connection 53, 54 or 55. Any water vapors thus formed are carried back to the separating chamber I2 through the conveyor and the vent pipe 56, so that a cooled, solid, substantially anhydrous soap is delivered to the second conveyor. The soap may be further cooled in the second conveyor, and if desired, may be hydrated tov some extent therein, being discharged into the atmosphere through the valve 58 in the form withvcertain soaps it is possible to secure of a continuously-moving stream. Cooling of the soap is carried to such a degree that upon exposure to the atmosphere, no deleterious discoloration or oxidation will result, and no peroxide will be formed, the resulting soap being neutral and extremely stable against rancidity and burning. It has been found that up to approximately 12% of Water may be added 'to and retained in the soap before extrusion through the valve 58 without destroying the friable nature ofthe soap in this embodiment of the process. This water may be introduced by means of the connection 59 inthe second conveyor I6. Satisfactory results may be obtained if the soap is cooled in the rst conveyor I5 to a value between the critical temperature mentioned in the preceding para- `graph and an upper value oi 300" F. However,

this temperature of 300 F. is not set forth aS limiting the invention in view of the fact that a friable product by cooling toa temperature which is somewhat above this figure.

In both of the above alternative modes of proglossy surface and is of a stratified character.

If not self-disintegrating, it easilybreaks up into small lumps and flakes which readily disintegrate upon application of pressure into smaller 4particles. Further, the resulting product is of light color, even when made kfrom the darker-colored fats r oils. 'Ihis unexpected result of bleaching the soap in the process is extremely valuable in making soap from such saponifiable materials as crude or refined palm oil or other naturally highly colored oils. In addition, the soap is extremely stable and neutral and is also of a high degree of purity,'since at the temperatures used in the vapor separating chamber substantially all of the impurities present in the fat or other saponifable material are destroyed or removed from the soap with the Water and the glycerine vapor. By reason of the cooling of the soap before contact with the atmosphere, I eliminate deleterious 'discoloration and oxidation, as well as formation of peroxide. One of the important features of the invention is that this cooling can be effected in a conned space out of contact with the air. 'I'he system shown also permits the cooling to be performed at subatmospheric pressures. The resulting soap formed by the alternative modes of procedure set forth above may be furnished as an article of manufacture to makers of pharmaceutical and cosmetic soaps, and the friable nature thereof obviates the difficulty heretofore encountered in grinding more or less plastic soap for such uses.

Quick cooling appears to facilitate the formation of .the incipient planes of fracture, resulting v in a. more friable product. As mentioned above, soap has a characteristic of not immediately returning to solid form when the temperature is reduced below the melting point. From this angle it will be clear that it is not essential to maintain the soap at the melting temperature while this soap is in the lower part of the Vapor separating'chamber I2 or in the first part of the conveyor I5. It is sufficient if the soap be 'cooled from molten condition (i. e., from semi-plastic, plastic or-strictly molten condition). Usually I find it desirable to utilize the jacket 49 to maintain the temperature of the soap substantially the same as when withdrawn from the vapor separating chamber, though some cooling can be permitted therein; The preferable manner of forming a friable product is to not materially cool the soap until it enters the second part of the conveyor l5. It is usually satisfactory with most soaps to maintain the temperature in the first portion of the conveyor I5 above 450 F., though this figure is not invariable. As the molten soap enters the Vicinity of the cooling means it is cooled from its molten condition to effect the formation of the incipient planes of fracture as the soap solidifles.

As a third alternative mode of operation of the apparatus shown in Figure l, it is-possible to form a soap product which is not of a friable nature but which is in the form of a plastic mass or a `iell-like soap product comparable to what is known in the art of kettle soap making as a finished kettle soap. In .forming this product the soap is cooled from the said molten condition, though it is not essential that the cooling be suddenlyefected. If desired, the' cooling may be performed in both' the first and second conveyors, being carried to such adegree that the soap will not discolor or oxidize upon exposure to the atmosphere. Further, production of this soap product is facilitated by adding additional quantities vof liquid or steam to the soapA in either the first or second conveyors, the quantity of liquid being usually above the 12% value hereinbefore mentioned, though not necessarily so if the soap is more slowly cooled. lIn. this connection any desired quantity of moisture may be added to the soap to facilitatethe formation of this plastic or jell-lilre` soap of non-friable nature expelled from the valve 58.v

In the second alternative mode of operation mentioned above, in which a frable soap product is produced which is not self-disintegrating when discharged from the second conveyor, I often find it desirable to reduce this product to granular or finely powdered condition directly as a part of the continuous process, rather than discharging the soap product into storage for later sub-A division. Figures 2 and 3 illustrate modifications which can be used in this regard.

In Figure 2 is shown such a modification including an apparatus for grinding lthe friable product. Instead of discharging through the valve 58, the second conveyor I6 may discharge directly into a third conveyor 1| preferably positioned at right angles to the conveyor I6. The third conveyor 1| may comprise a plurality of screw conveyor sections or flights 12, 13, 14 and 15 between which are interposed knife blade sections 16 shown in more detail in Figure 4 andincluding blades 11 extending between the spaced sections of the conveyor 1|. If desired, these knife blade sections may provide blades with sharp upper edges, though this is not always essential. 'I'he convolutions of the section 12 of the screw conveyor 1I take repeated shaving cuts from the end of the mass of soap being delivered into the conveyor 1I from the conveyor I6, as will be apparent from Figure 2. The soap thus cut from the soap advancing-in the conveyor '|6is forced by section 12 of the conveyor 1| against the knife blades 11'of the first knife blade section 16. The soap is thus subjected to a cutting action by the knife blades 11 due to the fact that these blades are stationary and the soap 'is turning in the conveyor section 12. Also, as the soap is forced through the knife blade sections 16 it is again cut by the rotating vanes of the adjacent end of the next conveyor section 13. This process is repeated as many times as necessary to secure the desired product. The number of stages will be determined by` the fineness of the product desired.

If desired, the subdivided material issuing from the discharge end of the conveyor 'H may be screened, the ccarser particles being returned to the first section of the conveyor 1|, by means not shown, in order to obtain a uniformly fine product. It is thus possible to make a finely powdered soap, suitable for pharmaceutical or cosmetic uses from the friable and brittle soap delivered from conveyor I6, or, by less intense grinding, a finely powdered or granular material marketable for certain detergent purposes.

The processs of the present invention is also capable of producing nished soap ign cake or bar sired products.

form for detergent purposes. In the modification of the apparatus shown in Figure 3, the conveyor I 6 discharges through a perforated plate 18 into a conveyor 19 of the screw type divided into a plurality of sections 80 between which are positioned knife'blade sections 16, such as shown in Figure 4, and perforated plates 8|. For this purpose the soap is ordinarily hydrated to a greater extent than in preparing the powdered soap above discussed. To accomplish this water or Wet steam may be introduced through the connections 59 of the conveyor i6 and also may be introduced int'o pipe connections 82 of the conveyor 19. During its progress through the conveyors I6 and 19 thel cooled soap from the conveyor 'I6 is plodded and repeatedly extruded by the knife blades 16 and perforated plates 8| respectively. builders or fillers may be introduced into the conveyor 19, for example, by means of a screw conveyor 83 connected to the conveyor 19. Also, perfumes and other liquid soap ingredients may be introduced through the pipe connections 59 and 82. The perforated plates 8l may have successively smaller apertures toward the discharge end of the conveyor 19, and it will be vunderstood that .the perforated plates may be used alone or4 the knife blade sections may be used alone, or

Figure 3. livered from the conveyor I 6, and which has ,been cooled from a molten and substantially anhydrous condition, is of uniform consistency throughout and can be plodded and extruded with a minimum of effort.

The apparatus shown in Figure 3 is also capable of producing a product similar to that known in the soap art as finished kettle soap,` which is a jell-like hydrated soap with the glycerine substantially removed, and which carries upwards of of water. By introducing the required amount of water through the pipe connections 59 and 82, and eliminating the addition of fillers and other soap builders, the soap from the conveyor I 6 may be easily plodded into the jell-like form known as finished kettle soap, which product may be then carried through the conventional framing, drying and plodding steps employed for kettle-made soap.

It will be noted that the invention above disclosed :provides a process and apparatus for continuously converting saponiflable material into marketable products by continuously contacting a saponiablematerial and a saponifying material, continuously removing water (and, if desired, the glycerlne) from the soap formed during the saponication step, and cooling the molten soap so as to render it easily convertible into de- It will further be noted that all of the steps `of the process from the mixing of the saponifiable and saponifying material to the discharge of the desired product from the process is carried out in a-closed system. Thereis no opportunity for air to become mixed or emulsied with the materials being treated and the heated soap being processed is prevented from contacting with the atmosphere, thus preventing discoloration and the formation of peroxides, which tend to cause rancidity and burning,

While I have herein described ar complete system,`it will be clear that various portions thereof are of utility and are novel irrespective of their lar form which nds utility regardless of how the molten soap is produced, and regardless of Whether or not the intermediate friable product is produced. Sudden cooling is thus-not essential in all uses of the invention, and the invention is not limited to the production of a, friable soap product, either as an end product or an intermediate product. As mentioned above, the invention also comprehends in various of its aspects the production of plastic, jell-like, or other forms of soap y Nor is it always essential to the inventive con- `cept that molten soap, within the definition set If desired,

use in the complete system. For instance, theV invention comprehends a novel system of converting the molten soap into powdered or granuforth above, be formed in the system disclosed. Soap in other conditions can be formed and the cooling, conveying, and conditioning means are of utility regardless of whether or not molten soap is supplied thereto.

While bestresults are obtained by removing glycerine from the soap, the invention is not in Iall instances limited thereto. Material quantities of glycerine can be allowed to remain in the soapif desired.

I believe it to be novel to cool the substantially anhydrous soap as it moves in a continuously advancing stream, and also to inject water into such a moving soap mass without permanently hydrating .the soap, removing the vapors as they are formed. So also, certain features of the system herein shown for saponification andvapor-separatlon arebelieved to be new without reference to the complete system. For instance, the systems for heating and introducing steam into the vapor separating chamber are novel, irrespective of how the soap is thereafter processed, and irrespective of whether the soap is collected in the bottom of the vapor separating chamber in molten condition. Such features find utility in saponifying systemseven when insufficient temperatures are developed or maintained to insure that the soap in the lower end of this chamber is in molten condition.

Various other features of the invention are novel. independent of the complete combination, and it is believed that the friable products produced are novel. A

This application is a division of application Serial No. 61,410, led January 29, 19'36, for Process and apparatus for making soap and productI thereof, which has now matured into Patent No. 2,142,983, dated January 3, 1939` It is to be understood that the invention is not Alimited to the details herein disclosed, but may be varied within the scope of the following claims.

Iclaim:

1. In an apparatus for continuously making soap from a saponiflable material by reaction therewith of an acueous solution of saponifying material, the combination of: 'a heating 'means providing an elongated reaction zone closed from the atmosphere; means delivering to said reaction zone proportioned quantities of said saponiable material and aqueousv solution of said saponifying material whereby saponication takes pl-ace in said reaction zone to form reaction products inf cluding soap; a separating means including a vapor separating chamber receiving said reaction products; means for heating said separating chamber; means for continuously removing vapor from said separating chamber at such a, rate as to maintain a vacuum therein; means for continuously withdrawing a stream of soap from said separating chamber without lmpairing said vacuum, said means including a Screw conveyor soap, at least two of said conveyor passages being angularly disposed relative to each other to intersect at an angle; and. means for cooling said soap in said conveyor system.

2. In an apparatus for making soap from a saponifiable material by reaction therewith of an aqueous solution of a saponifying material, the combination of a heating means providing an elongated reaction zone; means delivering to said reaction zone proportioned quantities of said saponiiiable material and aqueous solution of said saponifying material whereby saponitlcation Aasumen;

takes place in said reaction zone to form reaction products including soap; a separating means including a vapor separating chamber receiving said reaction products; means for supplying steam to said chamber; means for` continuously removing vaporfrom said separating chamber; and means for withdrawing soap from said separatlng chamber, said means including a conveyor housing, a screw conveyor rotatable therein and formed in flights, and means in said housing and extending between said nights to break up the advancing soap stream.

BENJALDN H. THURMAN. 

